EFFECTS OF MEDIUM STERILIZATION ON THE PRODUCTION OF ZARAGOZIC ACIDS BY THE FUNGUS LEPTODONTIDIUM-ELATIUS

The production of zaragozic acids by fermentation of the fungus Leptod ontidium elatius was examined at the 800-L fermenter scale under two d ifferent production medium batch sterilization conditions, Low product ion-medium heat input (R(0) = 33.4 min) resulted in a 4'-desacetoxy za ragozic acid C:4'-O-desacetyl zaragozic acid C:zaragozic acid C ratio of 0.53 : 0.60: 1.0. At a higher heat input (R(0) = 50.5 min), the rat io shifted to 1.0:0.66:1.0 with a corresponding 26% increase in total zaragozic acid production, This higher total zaragozic acid titer resu lted from an increase in the amount of 4'-desacetoxy zaragozic acid C produced while the levels of the other two analogues remained unchange d, Batch sterilization conditions also resulted in differences in grow th, carbon substrate consumption, and oxygen uptake rates, The structu res of the zaragozic acids produced suggest a precursor/end product re lationship, A biosynthetic model describing the synthesis of the three zaragozic acids listed above is postulated and used to explain the ef fects of production-medium heat input during sterilization.